Eastern Africa, part of sub-Saharan Africa comprising two traditionally recognized regions: East Africa, made up of Kenya, Tanzania, and Uganda; and the Horn of Africa, made up of Somalia, Djibouti, Eritrea, and Ethiopia.

Eastern Africa consists largely of plateaus and has most of the highest elevations in the continent. The two most striking highlands are in Ethiopia and Kenya, respectively, where large areas reach elevations of 6,500 to 10,000 feet (2,000 to 3,000 metres). Twin parallel rift valleys that are part of the East African Rift System run through the region. The Eastern, or Great, Rift Valley extends from the Red Sea’s junction with the Gulf of Aden southward across the highlands of Ethiopia and Kenya and continues on into Tanzania. The Western Rift Valley curves along the western borders of Uganda and Tanzania. Between the two rift valleys lies a plateau that comprises most of Uganda and western Tanzania and includes Lake Victoria. The volcanic massif of Kilimanjaro, the highest mountain in Africa, reaches 19,340 feet (5,895 metres) in northeastern Tanzania. The Horn of Africa, a major peninsular extension of the African mainland into the Arabian Sea, contains the vast lowland coastal plains of Somalia.

The climate of eastern Africa is generally tropical, though average temperatures tend to be reduced by the region’s high elevations. Precipitation also is affected by varying elevation: Uganda, Tanzania, and western Kenya receive plentiful rainfall, while Somalia, eastern Ethiopia, and northeastern Kenya receive far less. The region’s vegetation ranges from woodlands and grasslands in the wetter regions to thornbushes in semiarid areas. The grasslands of Tanzania and Kenya are renowned for their wildlife, in particular large migratory herds of ungulates (e.g., gnus, zebras, and gazelles) and predators (lions, hyenas, and leopards).

Eastern Africa is populated by 160 different ethnic groups or more, depending on the method of counting. Most of the peoples of Eritrea and Ethiopia—and some of those in Tanzania and Kenya—speak languages belonging to the Cushitic branch of the Afro-Asiatic languages. Speakers of Nilo-Saharan languages populate Uganda and the rift valley portions of Kenya and Tanzania, while speakers of Bantu languages constitute much of the remainder of these countries’ population.

The largest ethnic groups in eastern Africa are the Oromo, Cushitic speakers who occupy much of southern Ethiopia, and the related Somali, who occupy all of Somalia, southeastern Ethiopia, and much of Djibouti. The Afar are found in both Eritrea and Djibouti. The main ethnic groups of Eritrea, the Tigray and the Tigre, are speakers of Semitic languages. Both the Tigray and the Amhara, another Semitic-speaking group, dominate northwestern Ethiopia. The ethnic fabric in Kenya, Tanzania, and Uganda is much more fragmented, with many smaller peoples intermingled or occupying discrete territories. The largest numbers of Nilo-Saharan speakers belong to the Luo, Lango, Kalenjin, Maasai, and Karimojong peoples, while the principal Bantu-speaking ethnic groups are the Kikuyu, Chaga, and Kamba.

This article covers the history of the area from ancient times through the 20th century. Coverage of the region’s physical and human geography can be found in the article Africa. For discussion of the physical and human geography of individual countries in the region and of their late colonial and postcolonial history, seeDjibouti, Eritrea, Ethiopia, Kenya, Somalia, Tanzania, and Uganda. Area 1,420,236 square miles (3,678,394 square km). Pop. (2009 est.) 293,654,000.

East Africa

The coast until 1856

The earliest written accounts of the East African coast occur in the Periplus Maris Erythraei—apparently written by a Greek merchant living in Egypt in the second half of the 1st century ce—and in Ptolemy’s Guide to Geography, the East African section of which, in its extant form, probably represents a compilation of geographic knowledge available at Byzantium about 400. The Periplus describes in some detail the shore of what was to become northern Somalia. Ships sailed from there to western India to bring back cotton cloth, grain, oil, sugar, and ghee, while others moved down the Red Sea to the East African coast bringing cloaks, tunics, copper, and tin. Aromatic gums, tortoiseshell, ivory, and slaves were traded in return.

Because of offshore islands, better landing places, and wetter climate, Arab traders from about 700 seem to have preferred the East African coast to the south of modern Somalia. They sailed there with the northeast monsoon, returning home in the summer with the southwest. They dubbed the part of the coast to which they sailed Azania, or the Land of Zanj—by which they meant the land of the blacks and by which they knew it until the 10th century. South of Sarapion, Nikon, the Pyralaae Islands, and the island of Diorux (about whose precise location only speculation seems possible), the chief town was Rhapta, which may lie buried in the Rufiji delta of present-day Tanzania. Here the situation differed somewhat from that in the north, and, though tortoiseshell and rhinoceros horn were exported from there—as were quantities of ivory and coconut oil—no mention is made of slaves. Rhapta’s main imports were metal weapons and iron tools—suggesting that iron smelting was not yet known. Mafia Island, which lies out to sea here, could perhaps be Menouthias, the only island named in both the Periplus and the Guide, although this could also be either Pemba or Zanzibar (perhaps there has been a conflation of all three in the one name).

There is little information concerning the period until the 8th century. Greek and Roman coins have been found, and there are some accounts of overseas migrations to the coast. No settlements from this period have been found.

A new period opened, it seems, in the 9th century. The first identifiable building sites are dated from this time, and, according to Arab geographers, the East African coast was then generally thought of as being divided into four: (1) Berber (Amazigh) lands, which ran down the Somalian coast to the Shabeelle River, (2) Zanj proper, (3) the land of Sofala in present-day Mozambique, whence gold was beginning to be shipped by about the 10th century, and (4) a vaguely described land of Waq waq, beyond. The only island that is mentioned is Qanbalu, which appears to have been what is now Tanzania’s Pemba Island. Though there is some suggestion that in the 10th century the Muslims had not yet begun to move farther south than Somalia, on Qanbalu they soon became rulers of a pagan population, whose language they adopted. Moreover, at Zanzibar an extant Kūfic inscription (the only one) recording the construction of a mosque by Sheikh al-Sayyid Abū ʿImrān Mūsā ibn al-Ḥasan ibn Muḥammad in 1107 confirms that by this time substantial Muslim settlements had been established.

The main coastal settlements were situated on islands, largely, no doubt, because of the greater security these provided against attacks from the mainland; and their populations seem mostly to have been made up from migrants from the Persian Gulf—some from the great port of Sīrāf, others from near Bahrain—though conceivably some too came from Daybul, at the mouth of the Indus River, in northwestern India. They exported ivory (some of it went as far as China) and also tortoiseshell, ambergris, and leopard skins. Such trade goods as they obtained from the interior were apparently bought by barter at the coast.

Ruins at Kilwa, on the southern Tanzanian coast, probably date from the 9th or perhaps from the 8th century. They have revealed an extensive pre-Muslim settlement standing on the edge of what was the finest harbour on the coast. Though there is little evidence to suggest that its inhabitants had any buildings to begin with, wattle-and-daub dwellings appeared in due course, and by the 10th century short lengths of coral masonry wall were being built. The inhabitants, whose main local currency was cowrie shells, traded with the peoples of the Persian Gulf and, by the early 11th century, had first come under Muslim influence. By 1300, like the inhabitants of neighbouring Mafia, they were living in Muslim towns, the rulers of which were Shīʿites. Although no houses were being built of coral, stone mosques were being constructed.

External trade was increasing: glass beads were being imported from India, and porcelains, transshipped either in India or in the Persian Gulf, were arriving from China. There appears also to have been a rather extensive trade with the island of Madagascar.

The most important site of this period yet to have been found is at Manda, near Lamu, on the Kenyan coast. Apparently established in the 9th century, it is distinguished for its seawalls of coral blocks, each of which weighs up to a ton. Though the majority of its houses were of wattle and daub, there were also some of stone. Trade, which seems to have been by barter, was considerable, with the main export probably of ivory. Manda had close trading connections with the Persian Gulf—with Sīrāf in particular. It imported large quantities of Islamic pottery and, in the 9th and 10th centuries, Chinese porcelain. There is evidence of a considerable iron-smelting industry at Manda and of a lesser one at Kilwa.

The Shirazi migration

For much of the 13th century the most important coastal town was Mogadishu, a mercantile city on the Somalian coast to which new migrants came from the Persian Gulf and southern Arabia. Of these, the most important were called Shirazi, who, in the second half of the 12th century, had migrated southward to the Lamu islands, to Pemba, to Mafia, to the Comoro Islands, and to Kilwa, where by the end of the 12th century they had established a dynasty. Whether they were actually Persian in origin is somewhat doubtful. Though much troubled by wars, by the latter part of the 13th century they had made Kilwa second in importance only to Mogadishu. When the Kilwa throne was seized by Abū al-Mawāhib, major new developments ensued. Kilwa captured Mogadishu’s erstwhile monopoly of the gold trade with Sofala and exchanged cloth—much of it made at Kilwa—and glass beads for gold; and with the great wealth that resulted new pottery styles were developed, a marked increase in the import of Chinese porcelain occurred, and stone houses, which had hitherto been rare, became common. The great palace of Husuni Kubwa, with well over 100 rooms, was built at this time and had the distinction of being the largest single building in all sub-Saharan Africa. Husuni Ndogo, with its massive enclosure walls, was probably built at this time, too, as were the extensions to the great mosque at Kilwa. The architectural inspiration of these buildings was Arab, their craftsmanship was of a high standard, and the grammar of their inscriptions was impeccable. Kilwa declined in the late 14th century and revived in the first half of the 15th, but then—partly because of internal dynastic conflict but also partly because of diminishing profits from the gold trade—it declined again thereafter.

Elsewhere, especially on the Kenyan coastline, the first half of the 15th century seems to have been a period of much prosperity. Whether at Gede (south of Malindi) or at Songo Mnara (south of Kilwa), architectural styles were relatively uniform. Single-story stone houses, mostly of coral, were common. Each coastal settlement had a stone mosque, which, typically, centred upon a roofed rectangular hall divided by masonry pillars. Chinese imports arrived in ever larger quantities, and there are signs that eating bowls were beginning to come into more common use. Mombasa became a very substantial town, as did Pate, in the Lamu islands. The ruling classes of these towns were Muslims of mixed Arab and African descent who were mostly involved in trade; beneath them were African labourers who were often slaves and a transient Arab population. The impetus in this society was Islamic rather than African. It was bound by sea to the distant Islamic world, whence immigrants still arrived to settle on the East African coast, to intermarry with local people, and to adopt the Swahili language. The impact of these settlements was limited, while their influence upon the East African interior was nonexistent.

During the 15th century, Shirazi families continued to rule in Malindi, Mombasa, and Kilwa and at many lesser places along the coast. They also dominated Zanzibar and Pemba. The Nabahani, who were of Omani origin, ruled at Pate and were well-represented in Pemba as well. Coastal society derived a certain unity by its participation in a single trading network, by a common adherence to Islam, and by the ties of blood and marriage among its leading families. Politically, however, its city-states were largely independent, acknowledging no foreign control, and their limited resources confined their political activities to East Africa and to a variety of local rivalries—Zanzibar and Pemba, for example, appear frequently to have been divided between several local rulers. Mombasa occupied the premier position on this part of the coast, although its control over the area immediately to the north was disputed by its main rival, Malindi. Close connections seem to have existed between Mombasa and a number of places to the south. Its Shirazi rulers were able to mobilize military support from some of the inland peoples, and as a result of the place it had won in the trade of the northwestern Indian Ocean they had turned Mombasa into a prosperous town. Its population of about 10,000 compared with only 4,000 at Kilwa.

The Portuguese invasion

This was the situation on the East African coast when Portuguese ships under Vasco da Gama arrived in 1498. The manifestly superior military and naval technology of the Portuguese and the greater unity of their command enabled them, in the years that lay ahead, to mount assaults upon the ill-defended city-states. As early as 1502 the sheikh at Kilwa was obliged to agree to a tribute to the Portuguese, as the ruler of Zanzibar was later. Shortly afterward the Portuguese sacked both Kilwa and Mombasa and forced Lamu and Pate to submit. Within eight years of their arrival they had managed to dominate the coast and the trade routes that led from there to India.

The Portuguese became skilled at playing one small state against another, but their global enterprise was such that they did not immediately impose direct rule. This changed toward the end of the 16th century, however, when Turkish expeditions descending the northern coast with promises of assistance against the Portuguese encouraged the coast north of Pemba to revolt. This prompted the dispatch of Portuguese fleets from Goa, one of which, in 1589, sacked Mombasa and placed that city much more firmly under Portuguese control. This was helped by the death of Mombasa’s last Shirazi ruler, Shah ibn Mishhan, who, in leaving no clear successor, gave the Portuguese the opportunity to install Sheikh Aḥmad of Malindi in his place. In 1593, with an architect from Italy in charge and with masons from India to assist them, the Portuguese set about building their great Fort Jesus at Mombasa. In the following year it was occupied by a garrison of 100 men.

Fort Jesus, Mombasa, Kenya.

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With Mombasa’s downfall, the major hindrance to Portuguese power on the East African coast was overthrown. They installed garrisons elsewhere than at Mombasa and brought about the downfall of a number of Shirazi dynasties, and, although they did not exercise day-to-day control over local rulers, they did make them dependent on them for their position. (Local rulers were in particular required to pay regular tribute to the Portuguese king on pain of dethronement and even of death.)

Portugal’s chief interests were not imperial but economic. With Mombasa in their grip, they controlled the commercial system of the western Indian Ocean. Customs houses were opened at Mombasa and Pate, and ironware, weapons, beads, jewelry, cotton, and silks were imported. The main exports were ivory, gold, ambergris, and coral. There was a flourishing local trade in timber, pitch, rice, and cereals but few signs of any considerable traffic in slaves. Individual Portuguese traders often developed excellent relations with Swahilis in the coastal cities.

Though the Portuguese managed to ride out local rebellions into the 17th century, their authority over a much wider area was undermined by the rise of new powers on the Persian Gulf. Portugal lost Hormuz to the Persians in 1622 and Muscat to the imam of Oman in 1650. Two years later the Omanis launched their first major intervention into East Africa’s affairs when in response to a Mombasan appeal the imam sent ships to Pate and Zanzibar and killed their Portuguese inhabitants. As a consequence, Pate became the centre of East Africa’s resistance to Portuguese rule. The Portuguese responded in an equally bloody manner, but eventually, in 1696, in alliance with Pate, the imam of Oman sailed to East Africa with a fleet of more than 3,000 men to lay siege to Mombasa. Although Fort Jesus was reinforced, the great Portuguese stronghold finally fell to Sayf ibn Sulṭān in December 1698. A few years later Zanzibar, the last of Portugal’s allies in Eastern Africa, also fell to the imam.

The Omani ascendancy

There ensued, after the Omani victory, a century during which, despite a succession of Omani incursions, the East African coast remained very largely free from the dominance of any outside power. Oman itself suffered an invasion by the Persians and was long distracted by civil conflict. Its originally successful Yaʿrubid dynasty lost prestige as a consequence, fell from power, and was then superseded by the Āl Bū Saʿīdīs, who very soon found themselves preoccupied by conflicts at home. Moves against them also originated along the East African coast.

In 1727 Pate joined with the Portuguese to expel the Omanis, especially from Mombasa, where in 1728–29 Portuguese authority was momentarily restored. But the Mombasans wanted as little to be controlled by Portugal as by Muscat and soon evicted the Portuguese once again. Thereafter, Kilwa, Zanzibar, Lamu, and Pate largely kept themselves free from both Omani and Portuguese control. Distracted though it was by protracted internecine quarrels, Pate was preeminent in the Lamu archipelago and, like all the other coastal towns, was ambitious to preserve its independence.

Even so, Mombasa, in quite new circumstances, in the 18th century reached the apogee of its power as an independent city-state. The architects of this achievement were the Mazrui, an Omani clan who had provided some of the imam’s governors to Mombasa but who, because they were opposed to the Āl Bū Saʿīdīs, did not long persist in their allegiance to Muscat. They owed their authority in Mombasa itself to an ability to hold the balance between the rival factions in the Swahili population and also to their ability peacefully to overcome all but one of their dynastic successions. In 1746 a Mazrui notable, ʿAlī ibn Uthman al-Mazrui, overthrew an Omani force that had murdered his brother. Soon after he seized Pemba and, but for a family quarrel, might have won Zanzibar; his successor, Masʿūd ibn Nāṣir, initiated a pattern of cooperation with Pate, maintained close links with inland Nyika peoples, and established Mazrui dominance from the Pangani River to Malindi.

Both Mombasa and Pate were disastrously defeated by Lamu in the battle of Shela, about 1810. Pate’s preeminence in the Lamu islands was destroyed, Mombasa’s authority on the coast was diminished, and the way was open to Muscat’s great intrusion into East African affairs. Lamu appealed to Oman for a garrison to assist it, to which Sayyid Saʿīd of Muscat very soon responded.

The Āl Bū Saʿīdīs, who had captured Kilwa in 1785, maintained their principal footing upon the coast in Zanzibar, which had long held to its association with them. Thanks to the city’s growing success, from the end of the 18th century onward, in turning itself into the main entrepôt for the trade in the area south of Mombasa, Zanzibar soon rivaled Mombasa as the focal point for the whole coastline. As such, it was both developed and used by Sayyid Saʿīd ibn Sulṭān of Oman as the base for his growing ambitions. Having won the succession to Muscat after an internecine struggle following his father’s death in 1804, Saʿīd spent much of the next two decades establishing his authority there. (In this he was assisted by the British, who were much concerned to safeguard their route to India, which ran close to Muscat on its way past the Persian Gulf.) Then, in 1822, he wrested Pemba from Mazrui control and by 1824 had installed a Muscat garrison in Pate as well, thus bringing to an end the previous influence that the Mazrui had exercised.

Sensing the increasing threat from Muscat, the Mazrui appealed to the British for assistance. Though their application was formally denied, a British naval officer, Captain W.F. Owen, on his own initiative raised a British flag of protection over Mombasa in 1824. Since the British had no desire formally to extend their authority to East Africa at this time, let alone to break with their ally Saʿīd, it was hauled down in 1826. This gave Saʿīd his opportunity, and in 1828, 1829, and 1833 he mounted assaults upon Mombasa. But it was only when he successfully intervened in a dynastic dispute among the Mazrui, which followed on the death of a liwali in 1835, that he was able in 1837 to fasten his control over Mombasa and to topple the Mazrui from their position. His dominion along the whole coastline thus became assured, and after over a century’s interval the East African littoral once more found itself dominated by a single outside power. Though this outcome owed much to the inability of the coastal towns to unite against an invader, it owed much as well to the striking personality of Saʿīd himself, to his investment in a navy, to his force of Baloch soldiers (with which he supplemented his Omani levies), and to the support he received from the British.

It also stemmed from his intimate association with the major economic developments then taking place along the East African coast. These began with a marked growth in the previously marginal slave trade, particularly at first in the Kilwa region, more especially from 1780 to 1810 as a result of French demand for slaves in Mauritius and Bourbon. This was succeeded by the discovery that cloves could be successfully grown on Zanzibar and by the development of flourishing plantations. British pressure on Saʿīd to end the export of slaves to “Christian” markets came to fruition in 1822, when he reluctantly signed what became known as the Moresby Treaty. In the event, however, it made very little difference, either on the coast or in the interior, since slaves were being required in growing numbers for the plantations on both Zanzibar and Pemba and for export to the Persian Gulf and beyond.

Increasing commercial activity brought Sayyid Saʿīd sufficient wealth to buy ships and pay troops. It also attracted to the East African coast migrant Indians, who became heavily involved in the country’s economic expansion; and, together with the Arabs who were beginning to make profits from their clove plantations, Indians helped to finance the new upcountry trading caravans.

The increased economic activity that centred upon the islands of Zanzibar and Pemba served to enhance the importance of the smaller towns that stood on the mainland opposite. It also attracted an influx of European traders, of which the most important were the Americans. They were the first Westerners to conclude a trade agreement with Saʿīd (1833) and the first also to establish a consul at Zanzibar (1837). (Their prime achievement was to capture the cloth trade to East Africa—so that cheap cotton cloth thenceforth came to be known there as Americani.) The British followed with a trade agreement in 1839 and a consul in 1841. The French made similar provisions in 1844, and some Germans from the Hanseatic towns moved in at about the same time. British trade, however, never flourished and in fact died away; but by 1856 the United States and France were both making purchases in East Africa of more than $500,000 a year, while exports to India, particularly British India, were higher still. Some of the main items of trade, such as ivory, were traditional, but copal, sesame, cloves, cowries, hides, and coconut oil were also important. Because of this increased activity, Saʿīd’s economy in due course became less dependent upon the export of slaves, and he therefore showed himself more ready than he might otherwise have been to accept the so-called Hamerton Treaty of 1845, by which the export of slaves to his Arabian dominions was forbidden.

Since by this time the revenues from Saʿīd’s East African territories had overtaken those he received from Oman, it is understandable that in 1840 he should have transferred his own capital from Muscat to Zanzibar. At his death in 1856, Zanzibar was firmly established as the East African coast’s main centre, from which major new incursions into the interior had begun to radiate extensively.

The interior before the colonial era

The coast was never more than East Africa’s fringe. Beyond the harsh nyika, or wilderness, which lay immediately inland and was nowhere pierced by a long, navigable river, thornbush country extended to the south, sometimes interspersed with pleasanter plains toward the centre, while to the north cooler forested highlands ran into harsher country. Westward lay the Great Rift Valley and, beyond, the regions of the great lakes whence the Nile ran northward through its usually impassable marshes.

Since there are no written records antedating the last century or so for this region, its history has to be deduced from often uncertain linguistic, cultural, and anthropological evidence; from oral traditions—where they are available, which at best is only for recent centuries; and from archaeological findings. Since investigations and analyses are still at a very early stage and since the first hypotheses have proved vulnerable to criticism, the statements that follow must be only tentative. Furthermore, all accounts of tribal migration must allow for innumerable short-run moves and may refer only to small—if important—minorities. They must also take account of probable interactions with other peoples en route and often, indeed, of extensive absorption. Above all, care must be exercised over anachronistic concepts of tribe. Moreover, bolder categories such as Bantu are strictly only linguistic and must be treated with caution.

Two features of the pre-19th-century period may be stressed: first, although it seems to have been in this part of Africa that humans first developed, in the three or four most recent millennia the key innovations in human evolution seem to have occurred elsewhere; second, the extensive agricultural revolution in East Africa, which took place during this time, had the vital consequence that sizable populations grew up in areas of adequate rainfall, which could not be easily brushed aside by subsequent alien invaders.

During the earlier stages of the Stone Age down to about 50,000 bce, hand-ax industries were established in the Rift Valley areas of Kenya and of Tanzania (especially at Olduvai Gorge) and along the Kagera River in Uganda. During the Mesolithic period (thence to c. 10,000 bce), new stone-tool-making techniques evolved, and the use of fire was mastered. Spreading to other parts of East Africa, in the Neolithic period humans clustered into specialized hunting-and-gathering communities from which may have developed some still-existing ways of life. The largest number of relevant sites is close to the homeland of the Hadzapi—the last contemporary hunters and gatherers—and to that of the Sandawe, who are physically and linguistically akin to the San of southern Africa. Remnants of other hunting and gathering communities—such as the Twa and Mbuti of western Uganda—or at least the memory of them, are found in many places. Latterly, they often lived in precisely those highland regions where agriculture and animal domestication in East Africa first occurred.

Food production and the keeping of cattle seem to have begun in the highland and Rift Valley regions of Kenya and of northern Tanzania in the 1st millennium bce and to have derived from peoples who were probably southern Cushites from Ethiopia. Some traces of these interlopers remain among, for example, the Iraqw of Tanzania, and it may be that the age-old systems of irrigation found throughout this region owe their origins to this period as well. Agriculture preceded the smelting of iron in these areas, and hunting and gathering continued to be important for the domestic economy. It looks as if in due course southern Cushites spread deep into what is now southern Tanzania, but, so far as has been ascertained, food production did not develop in the period bce elsewhere in Tanzania, nor in what is now Uganda.

The spread of ironworking and the Bantu migrations

It is still far from clear when and whence iron smelting spread to the East African interior. Certainly there was no swift or complete transfer from stone to iron. At Engaruka, for example, in that same region of the Rift Valley in northern Tanzania, a major Iron Age site, which was both an important and concentrated agricultural settlement using irrigation, seems to have been occupied for over a thousand years. Significantly, its styles of pottery do not seem to have been related to those that became widespread in the 1st millennium ce. It is a reasonable assumption that its inhabitants were Cushitic speakers, but it seems that its major period belongs to the middle of the 2nd millennium ce.

The major occurrences of the 1st millennium ce involved the spread of agriculture—more particularly, the cultivation of the banana—to the remaining areas of East Africa. Simultaneously or perhaps previously went the spread of ironworking, and fairly certainly too the diffusion of Bantu languages—except in the core of the Cushitic wedge and to the north of an east-west line through Lake Kyoga. If, as seems probable, proto-Bantu languages had their origins in the eastern interior of West Africa, it does not seem inconceivable that over a lengthy period of time some of its speakers, probably carrying with them a knowledge of grain agriculture and conceivably a knowledge of ironworking, should have diffused along the tributaries of the Congo River to the savanna country south of the Congo forest into what is now the region of Katanga (Shaba) in Congo (Kinshasa). Nor does it seem inconceivable that the banana, originally an Indonesian plant particularly suitable in tropical conditions, should have spread to that same region up the Zambezi valley (certainly the Malayo-Polynesian influences in Madagascar in the 1st millennium ce are well attested in other respects). At all events, the linguistic and archaeological arguments for a fairly rapid eastward and northward expansion during the 1st millennium ce from the Katanga area now have wide acceptance. Bantu languages came to dominate most of this region (many Cushitic speakers in what is now Tanzania seem to have switched over to them or to have been eliminated). More varieties of banana developed in East Africa than anywhere else in the world. Ironworking was soon prevalent, and, where rainfall, soil nutrients, and the absence of the tsetse fly allowed, population growth increased decisively.

The early interlacustrine kingdoms

Sometime before the middle of the 2nd millennium ce, some of the most interesting developments were occurring in the interlacustrine area—i.e., the region bounded by Lakes Victoria, Kyoga, Albert, Edward, and Tanganyika. Vague accounts of rulerships in various parts of this area date from the first half of the 2nd millennium ce, and it is at least possible that they existed—though they may well have been judicial arbitrators or ritual leaders rather than more strictly political figures. Whether they had their origins in roving Cushitic or Nilotic cattle keepers from the north or northeast—as has been variously suggested—is impossible to say, though some such explanation would not be difficult to believe. What seems certain is that about the middle of the present millennium a sudden cultural political climax was marked by a short-lived, though widely acknowledged, dynasty of Chwezi rulers.

The Chwezi people are frequently associated with the great earthwork sites at Bigo, Mubende, Munsa, Kibengo, and Bugoma, in western Uganda. That at Mubende seems to have been a religious centre. The largest is at Bigo, where a ditch system, more than 6.5 miles (10.5 km) long, some of it cut out of rock, encloses a large grazing area on a riverbank. It looks as if it comprised both a royal capital and a well-defended cattle enclosure. Its construction must certainly have required a considerable mobilization of labour—which, apart from indicating that it must have been the work of a substantial political power, would support the view that the distinction between cultivators and a pastoral aristocracy, which later became typical of this area, is of very long standing. Radioactive carbon dating suggests Bigo was occupied from the mid-14th to the early 16th century. This correlates with the evidence of oral tradition that around the turn of the 15th century the Chwezi were supplanted in the north by Luo rulers of the Bito clan (who provided the dynasties that ruled in Bunyoro, Koki, Buganda, and parts of Busoga) and that they were superseded to the south by various Hima rulers of the Hinda clan (in Ankole, Buhaya, Busubi, and around to the southeast of Lake Victoria). Under these, and the corresponding Nyiginya dynasty in Rwanda, powerful traditional rulerships among the interlacustrine Bantu persisted after the middle of the 20th century.

Their relatively common experience was reinforced in the aftermath of the Chwezi dynasty by the prevalence among them of a variety of (often commemorative) Chwezi religious movements. In some areas these took the form of spirit-possession cults; in others, pantheons of deities were developed. In various guises—sometimes in support of the existing political order, sometimes against it—they spread into Bunyoro, Buganda, Busoga, Ankole, Buha, Rwanda, Burundi, and even to Nyamwezi country, in what is now Tanzania. So extensive a diffusion of a basically common religious tradition in any other part of the East African interior before the much later arrival of Islam and Christianity was rare indeed.

The chieftainships of the southern savanna

In northwestern Tanzania, dynasties of a pre-Chwezi kind apparently spread from the interlacustrine area during the middle centuries of the present millennium. Ntemi (as the office was called) became prevalent among both the Sukuma and the Nyamwezi. They (the ntemi) were probably as much ritual leaders as political rulers; certainly they do not seem to have exercised before the 19th century a “state” authority that was characteristic of the later interlacustrine rulers. By roughly the 16th century there may have been an extension of this style of chieftainship southward into southwestern Tanzania. At all events, the chiefly groups among the Nyamwanga, the Nyika, the Safwa, the Ngonde, the Kinga, the Bena, the Pangwa, the Hehe, and the Sangu have common traditions of origin, and it seems clear that they are to be distinguished from their significantly different, matrilineal neighbours in southern Tanzania, Zambia, and Congo (Kinshasa). There also seem to have been secondary movements of ntemi-like institutions in the 18th century to Ugogo, Safwa, Kaguru, Kilimanjaro, and Usambara. At the same time, the development of chieftainships in these other areas of Tanzania may originally have occurred independently of influences from elsewhere.

Northeastern Bantu

The spread of some Bantu to the northern coast of East Africa during the 1st millennium ce is supported by the memory of a settlement area named Shungwaya situated to the north of the Tana River. Shungwaya appears to have had its heyday as a Bantu settlement area between perhaps the 12th and the 15th centuries, after which it was subjected to a full-scale invasion of Cushitic-speaking Oromo peoples from the Horn of Africa. There is controversy as to whether the ancestors of the present Kamba and Kikuyu of Kenya were from Shungwaya, but it would seem that they probably broke away from there some time before the Oromo onslaught. It has been suggested, indeed, that the Kikuyu spread through their present territories from 1400 to 1800. The old Cushitic wedge checked them from spreading farther westward. This extended, as it would seem to have done for two or more millennia past, over both sides of the Kenyan and northern Tanzanian Rift Valley, but in the middle of the present millennium it was subjected to one of the multiple waves of invading Nilotic peoples—who were partly agriculturists and partly pastoralists—that moved into much of the northern and northwestern parts of East Africa.

The Nilotic migrations

The supersession of the Chwezi by Luo dynasties in the northern interlacustrine region at about the end of the 15th century resulted from the migrations of Nilotic peoples southward—in this instance, it has seemed, from a cradleland in what are now Sudan and South Sudan.

For some 18 generations or so Bito rulers of Luo origin held sway over the kingdom of Bunyoro-Kitara, to the east of Lake Albert. Though at first their dominion seems to have been widely extended, they began to be rivaled in the 16th and 17th centuries by the rise of Buganda, under its ruler, or kabaka. Working on interior lines and based upon a particularly fertile region, Buganda developed a strength and cohesion that from the 18th century onward was to make it—with Rwanda—one of the two most formidable kingdoms of the region.

The Luo rulers and such followers as had accompanied them were soon fully absorbed into the Bantu population of these kingdoms. Immediately to the north (where the Bantu did not extend) there occurred the greatest independent expansion of the Luo peoples, who formed the Acholi; provided ruling groups for peoples to the west who came to be called Alur; and bred the Jopaluo and Jopadhola to the east and also the sizable Luo populations who, between the mid-16th and the mid-18th centuries, came to settle on the northern side of Winam Bay to the northeast of Lake Victoria and spread thereafter to its southern shore as well.

Over to the east, into the former Cushitic domain that centred upon the Rift Valley, there appears to have been, in about the middle of the present millennium, a great expansion of Kalenjin peoples. These Highland Nilotes (as distinguished from, among others, River-Lake Nilotes such as the Luo), seem to have absorbed most of the previous southern Cushites who remained there and also to have successfully held the core of this ancient wedge, if not its earlier dimensions, against further Bantu incursions. By 1700, however, a second expansion into this old protrusion was beginning. During the 18th century the Maasai (Plains Nilotes, as they are sometimes called) spread over most of the area, until they came to be found as far south as Gogo country in central Tanzania. Already divided into pure-pastoralist and mixed-agriculturist subtribes, they were soon to be found to the east near Kilimanjaro. The earlier Kalenjin thus found themselves confined to the hillier country between the Rift Valley and Lake Victoria, where—constituting the Keyu (Elgeyo), the Suk (Pokot), the Nandi, the Kipsikis, and the Tatoga of more recent times—they entered into a variety of interactions with their various Luo and Bantu neighbours. Farther to the north in the areas beyond Mount Elgon a shorter-run series of migrations by other Plains Nilotes was simultaneously taking place. First, in the 17th century, the Lango began moving southwestward (and became much affected by their River-Lake Nilotic neighbours, the Acholi). Then, in the 18th century, the Teso, Karimojong, and others began also to move in various southward directions.

It has been suggested that all these Highland and Plains Nilotic migrations were set off, both before and after the middle of the present millennium, by successive pressures from the Oromo to the north. Like the Oromo, the Nilotic peoples lacked any firmly institutionalized political power, and their leaders were often less important than the elders of their clans. Indeed, Nilotes established “states” only where, as in the interlacustrine area over to the west, they came to rule other peoples who may very well have had traditions of rulership before they arrived. Such distinctions were to be of immense importance for the future.

Pressure on the southern chieftainships

With the breakup of their main body, at the north end of Lake Nyasa, after 1845, some parties of Ngoni moved northward. Some Ngoni groups made their way to Songea; another struck north to Lake Victoria. They carried, to the area west of Lake Tanganyika, a new style of raiding and appear to have precipitated among such peoples as the Holoholo and the Ndendehule, the Sangu, and the Bena—in part, at least, as a safeguard against Ngoni raids—the creation of new political institutions, including more powerful rulerships. The most notable of such developments were, in the first place, among the Hehe, where, under Munyigumba and then on his death, in 1879, under his son Mkwawa, a powerful state was built up; then among the Nyamwezi, where between 1870 and 1884 the warrior chief Mirambo established a powerful personal rulership; and also among the Kimbu, where, between 1870 and 1884, Nyungu and his ruga-rugas (or bands of warriors) created a dominion that survived his death.

Nothing quite so striking occurred to the northeast. Conflict persisted between the smaller Chaga rulers on Kilimanjaro. In the mid-19th century, Kimweri enjoyed a considerable dominion in the region of the Usambara Mountains, but on his death in the 1860s his rulership disintegrated. Further such disintegrations occurred in the 19th century among the rulerships of Buha and Buzinza, at the south end of Lake Victoria, and among the Buhaya kingdoms on its eastern shore. The kingdom of Mpororo, to the west of Buhaya, had already broken up. By the 1890s its neighbour Nkore seems to have been in danger of disintegrating as well. Earlier in the century Toro, to its north, had broken away from Bunyoro, previously the most extensive of the kingdoms in this area, while fragmentation was almost endemic among the Busoga kingdoms to the east.

Rwanda and Buganda

But there were also growing points in the interlacustrine area, where one of the largest kingdoms, Rwanda, consolidated its rear by annexing Lake Kivu, then, in the aftermath of a succession war, swallowed the small kingdom of Gissaka, to its east. It failed to defeat Burundi, to the south, but under its mwami, or ruler, Kigeri IV (who reorganized its military forces) it extended its control by raiding to the north.

Major states, peoples, and trade routes of eastern Africa, c. 1850.

Encyclopædia Britannica, Inc.

Its power was equaled in this region only by the kingdom of Buganda. Having annexed the large area of Buddu, to its southwest, in the late 18th century, Buganda thereafter generally refrained from any further territorial extensions. Its rulers steadily increased their authority at home by enhancing the power of appointed chiefs at the expense of the clan leaders, while abroad they preferred to make satellites rather than subjects of their neighbours. They had a good deal of success eastward in Busoga and southward along the western shore of Lake Victoria and around its southern rim. In the 1870s and ’80s Buganda’s protégés were on several occasions installed in petty rulerships in Busoga. In 1869 Bunyoro successfully survived Buganda interference in one of its succession conflicts (as Nkore did in 1878) and indeed in the 1870s and ’80s was renewing its strength. Bunyoro’s improved position turned much on its new military formations, the abarasura, while Buganda’s successful predation owed a good deal to its new military efforts under the mujasi, or military commander, as well as to the building of a formidable fleet of canoes.

The Luo and Maasai

To the north and northeast the previous migrations of the Luo from west to east were followed in the 19th century by a new wave of migrations from east to west. The Lango, for example, further expanded in two southward and westward waves toward Lake Kyoga and toward the Victoria Nile, where they ran up against the Acholi. To their south the Teso and the Kumam were also moving west and south. A flourishing trading network developed around Lake Kyoga.

Activity was rife also among the pastoral peoples to the east. In about 1850 the Turkana began to migrate from a base west of Lake Rudolf. Southward stood the Maasai, the warrior people of the plains and open plateaus north and south of the string of Rift Valley lakes west of Mount Kenya. From 1830 onward their various subtribes were engaged, under the auspices of their rival laibons, or ritual leaders—among whom Mbatian, who succeeded his father, Subet, in 1866, was the most famous—in a succession of internecine conflicts largely over cattle and grazing grounds. Their wars denuded the Laikipia and Uasin Gishu plateaus of their former Maasai, the so-called Wakwavi, who, being deprived of their cattle, switched to agriculture. They also helped the Nandi, who, with the Uasin Gishu Maasai now troubling them no more, took to raiding on their own account from a base between the Rift Valley and Lake Victoria. Under the leadership of their laibon-like orkoiyots, the Nandi and their kinfolk, the Kipsikis, were soon the new powers in the land. Some of their neighbours who lived in open country put up defense works against them—the Baluyia, to the west, for example, built mud walls around their villages—while others, such as the Teita, the Kamba, and the Kikuyu, who lived on higher ground and in forest country, were rather better placed and from their carefully guarded fastnesses could defy the Maasai. On the edges of their country they even entered into some permanent trade and marriage relations with the Maasai. Where the soil was fertile, moreover, such people considerably increased their populations. Though they had no chiefs, “prominent men” were accorded a recognized status among them, and by the close of the century some of these were fighting each other for local supremacy.

Trade with the coast

On the coast, following the death, in 1856, of Sayyid Saʿīd, his erstwhile dominions in East Africa were split off from the imamate of Muscat. By 1873 the authority of the Āl Bū Saʿīdī sultans on Zanzibar itself became complete, although there were still revolts against them on the coast—particularly at Pate and Mombasa (where the Mazrui retained their preeminence despite successive defeats)—and at Kilwa, to the south. This arose chiefly from the sultan’s acceptance of the further measures against the East African slave trade pressed upon him by the British consul at his court. By the 1860s some 7,000 or so slaves were being sold annually in the Zanzibar slave market, but in 1873 a treaty with the British closed the market at Zanzibar, and Sultan Barghash, by two proclamations in 1876, reduced the export from the mainland to a trickle. As it happened, however, there was then a final period of unprecedented slaving on the mainland, where the trade in slaves had generally been closely connected with the trade in ivory and the demand for porters was still considerable.

Trade in the East African interior began in African hands. In the southern regions Bisa, Yao, Fipa, and Nyamwezi traders were long active over a wide area. By the early 19th century Kamba traders had begun regularly to move northwestward between the Rift Valley and the sea. Indeed, it was Africans who usually arrived first to trade at the coast, rather than the Zanzibaris, who first moved inland. Zanzibari caravans had, however, begun to thrust inland before the end of the 18th century. Their main route thereafter struck immediately to the west and soon made Tabora their chief upcountry base. From there some traders went due west to Ujiji and across Lake Tanganyika to found, in the latter part of the 19th century, slave-based Arab states upon the Luapula and the upper reaches of the Congo. In these areas some of those who crossed the Nyasa-Tanganyika watershed (which was often approached from farther down the East African coast) were involved as well, while others went northwestward and captured the trade on the south and west sides of Lake Victoria. Here they were mostly kept out of Rwanda, but they were welcomed in both Buganda and Bunyoro and largely forestalled other traders who, after 1841, were thrusting up the Nile from Khartoum. They forestalled, too, the coastal traders moving inland from Mombasa, who seemed unable to establish themselves beyond Kilimanjaro on the south side of Lake Victoria. These Mombasa traders only captured the Kamba trade by first moving out beyond it to the west. By the 1880s, however, they were operating both in the Mount Kenya region and around Winam Bay and were even reaching north toward Lake Rudolf.

Major states, peoples, and trade routes of eastern Africa, c. 1850.

Encyclopædia Britannica, Inc.

The colonial era

Suggestions that he might at this time establish his dominion over the East African interior prompted Sultan Barghash to send a Baloch force to Tabora, but the idea was never pursued. A comparable notion, however, led Khedive Ismāʿīl Pasha of Egypt to appoint in 1869 the Englishman Samuel White Baker as governor of the Equatorial Province of the Sudan, so that Baker might carry the Egyptian flag to the East African lakes. Though Baker reached as far south as Bunyoro in 1872, he was soon obliged to leave. His successor, Charles George Gordon, proposed to circumvent both Bunyoro and Buganda by going straight up the Nile’s banks. But Mutesa I, kabaka of Buganda, frustrated Gordon’s efforts on the Nile, and by the early 1880s, with bankruptcy in Egypt and the Mahdist revolt in the Sudan, only remnants of the Egyptian enterprise remained.

The Egyptian incursion had been the climax to the search by many European explorers for the headwaters of the Nile—a quest that had obsessed the later years of the Scottish missionary David Livingstone and had prompted the discovery in 1858 of Lake Tanganyika by the English expedition of Richard Burton and John Hanning Speke. Speke returned first to discover Lake Victoria in 1858 and then with James Grant in 1862 became the first white man to set eyes on the source of the Nile, which Speke named Ripon Falls. By circumnavigating Lake Victoria 12 years later, Henry Morton Stanley stilled the controversy that had ensued in Europe over Speke’s claim.

Missionary activity

The revelations of these explorers, the example of David Livingstone, concern in western Europe over the East African slave trade, and the Roman Catholic and evangelical fervour that existed there inspired the invasion of the East African interior by a motley collection of Christian missionary enterprises. Johann Ludwig Krapf and Johannes Rebmann of the Church Missionary Society, who had worked inland from Mombasa and had, in the 1840s and ’50s, journeyed to the foothills of Mount Kenya and Kilimanjaro, were followed by a British Methodist mission. Roman Catholic missionaries reached Zanzibar in 1860 and settled at Bagamoyo in 1868. An Anglo-Catholic mission first tried to establish itself in the Shire highlands, then in 1864 transferred to Zanzibar. Anglican missionaries arriving in Buganda in the mid-1870s at the request of Kabaka Mutesa were soon followed by Catholic White Fathers—there and elsewhere on Zanzibar’s Tabora route—while the London Missionary Society sent men both to Unyamwezi and to Lake Tanganyika.

There were, of course, a number of localized religious movements among the peoples of East Africa during the 19th century. These included the Mbari cult among the Nyakyusa, the Nyabingi in Rwanda, and the Yakany movement north of Mount Ruwenzori. None of them, however, spread in quite the way that the Chwezi movement had earlier. Islam, on the other hand—spread widely at the instance of the Zanzibari traders and long established on the coast—had secured a scattering of converts in the interior as in the key kingdom of Buganda.

This was the scene onto which Christian missionaries first entered. Although by 1885 there were nearly 300 of them in East Africa, they did not initially win many converts, and those they at first obtained came only from among freed slaves and refugees from local wars. After 1880, however, they made important conversions in Buganda, and by the end of the century Christianity was spreading in the Lake Victoria area over most of the region in which the Chwezi movement had previously percolated—and before very long over a much larger area as well.

Partition by Germany and Britain

Philanthropic, commercial, and eventually imperialist ventures followed these evangelical endeavours. Nothing of great moment, however, occurred until 1885, when a German, Carl Peters, riding a tide of diplomatic hostility between Germany and Britain in Europe, secured the grant of an imperial charter for his German East Africa Company. With this the European scramble for Africa began. In east-central Africa the key occurrence was the Anglo-German Agreement of 1886, by which the two parties agreed that their spheres of influence in East Africa should be divided by a line running from south of Mombasa, then north of Kilimanjaro to a point on the eastern shore of Lake Victoria. This began the extraordinary process by which the territories and subsequently the nations of East Africa were blocked out first upon the maps far away in Europe and only later upon the ground in East Africa itself. The agreement put the area to the north (most of modern Kenya) under British influence and the area to the south (Tanganyika; modern mainland Tanzania) under German influence. The Anglo-German Agreement of 1890 placed additional territory (most of modern Uganda) under British influence.

Map of Central Africa, from the 10th edition of Encyclopædia Britannica, …

Encyclopædia Britannica, Inc.

Kenya was proclaimed a British protectorate in 1895 and a crown colony in 1920. Most of what is now Uganda was formally proclaimed a British protectorate in 1894, with additional areas being added to the protectorate in the following years. Tanganyika was declared a German protectorate in 1891. During World War I, Britain captured the German holdings, which became a British mandate in 1920. Britain retained control of Tanganyika after World War II when it became a United Nations trust territory. Tanganyika gained independence in 1961 and in 1964 merged with Zanzibar, later taking the name Tanzania. Uganda gained its independence in 1962, and Kenya became fully independent in 1963.